According to audio123’s review of the TO65 over on Head-Fi the IEM is “politely smooth” with its laid back treble (as compared to the TO150. Like the TO150 the TO65 is a single dynamic driver earbud. From one online market site it appears that the difference between the TO65, TO150 and TO200 is simply the impedance with the prices of all three within a few dollars of each other.
Pros – Smooth, Stage, Detachable Cable
Cons – More Extension